RICE DISEASE MANAGEMENT: INDUSTRY APPROACHES AND PERSPECTIVES

JM BONMAN

DuPont Agricultural Products, Stine-Haskell Research Center, PO Box 30, Newark, DE 19711, USA

Traditionally plant pathologists working in the crop protection industry have viewed rice disease management differently than have scientists working in institutions supported by the public sector. This paper contrasts these viewpoints and suggests public and private sector approaches to rice disease management may converge in the future.

Present tactics and targets
Industry sees rice disease management in a market context. The primary disease management tactic of industry has been the use of fungicides, because the value of new products can be captured to generate profit for stockholders and to support investment in further research. This research includes not only the search for new products, but also extensive laboratory and field work to generate environmental, health, and safety data and to understand how best to use the new products [1]. Industry average investments from discovery to first sales currently exceeds $100 million per molecule with future increases expected. Other technologies have not yet provided the same opportunities to consistently "capture value" in the marketplace.

Japanese rice growers spend more than $600 million per year to manage rice diseases and, consequently, Japan is the most important rice fungicide market worldwide. Rice blast (causal agent = Pyricularia grisea ) is the most important rice disease target from this perspective because about $400 million per year is spent on blast fungicides in Japan. Sheath blight (causal agent = Rhizoctonia solani) is of secondary importance, because less is spent for its control.

Public sector researchers see rice diseases from the perspective of total grain yield losses or as constraints to higher productivity. Using such criteria as a measure of importance, China, India and Indonesia (total rice area = 85 million ha) would be of greater importance than Japan (rice area = 2 million ha) as "target markets." By the same criteria, sheath blight would be more important than blast because it is more widespread and will cause increasing losses as production intensifies in irrigated tropical rice-growing environments. Public sector research has also been more diverse in its promotion of disease management tactics, using cultural methods, biological control, and host resistance in addition to chemical tools to control specific diseases in various rice production systems. This approach has also taken a wider view of targets, including virus and bacterial diseases that are not industry targets because no current market exists for products to control them.

In addition to disease management tactics and targets, industry and the public sector have had differing experiences assessing the possible broader effects of the technologies they develop. Because of regulation by governments worldwide, industry expends great effort assessing the human and environmental safety of new disease control tools. Public sector research is becoming more involved with this issue as new biotechnological innovations are applied to the tactics of resistance breeding and biological control [2].

Future trends
The agricultural products market is undergoing an integration between the seed and agrochemicals industries. This integration may provide new opportunities for cooperation between public and private sector researchers. Crop cultivars are being viewed as vehicles for other value-adding traits, including disease resistance. In rice, this trend is also evident with recent advances in rice biotechnology and hybrid development. In the future it is likely that more private companies will conduct research in the field of breeding for disease resistance, will patent inventions, and will eventually market new products in the form of disease resistant cultivars and perhaps combinations of host resistance and chemicals. Such new products will also fit a trend towards focusing more on the individual grower as the customer, rather than solely on product distributors.

>References
1. Hamlen RA, Labit B, Bruhn J, Holliday MJ, Smith CM, Shillingford CA, 1997. Environmentally Safe Approaches to Crop Disease Control, pp. 65-92.
2. Mathre D, 1997. Phytopathology News, p. 173.